This invention relates generally to gas turbine engine nacelle assemblies and, more particularly, to methods and apparatus for an integrated inlet design for a nacelle assembly.
Some known nacelle assemblies used with turbine engines include a plurality of components that disrupt aerodynamic flow of the nacelle assembly with a plurality of circumferential and axial gaps and steps defined between the components. For example, at least one known nacelle assembly includes an inlet lip, an inlet outer barrel, and a fan cowl that define an outer flow surface of the nacelle assembly. Moreover, within some nacelle assemblies, some known components include a plurality of segments, which define additional gaps and steps on the outer flow surface. For example, at least one known nacelle assembly used in a large high-bypass engine includes an inlet lip defined by a plurality of radial segments.
Within some turbine engines, at least some of the components and at least some segments of the components used in the nacelle assembly are coupled in position within the nacelle assembly with a plurality of mechanical fasteners. For example, mechanical fasteners may secure a bulkhead that is positioned internal to the inlet lip. The mechanical fasteners, because of their orientation, also disrupt aerodynamic flow of the nacelle assembly. More specifically, in the bulkhead example, heads of the mechanical fasteners are exposed on the outer surface of the nacelle assembly and are positioned directly in the outer flow path. In addition to the exposed heads of the mechanical fasteners, other gaps and/or steps in the nacelle assembly may inhibit laminar flow over the outer flow surface of the nacelle assembly, and may increase aerodynamic drag. Operating a turbine engine with increased aerodynamic drag may reduce fuel burn efficiency.